Synthese und Röntgenkristallstruktur eines (15E)-Dihydrobilatrien-abc-Derivats

The crystal structure of the (15E)-configurated 2,3-dihydrobilatriene-abc2, representing a model compound for the active form of the phytochrome chromophore, was determined at room temperature and at 97 K. Compared to the crystal structure of the corresponding (15Z)-derivative1, the molecule of2 shows a similar helix conformation, but with considerably larger helix pitch. The azide hydrogen atoms are localized at the nitrogen atoms of rings A, C and D. The distribution of bond lengths and bond angles is compatible with previous crystal structures and with the canonical formula. Tautomeric form, conformation and crystal packing are understandable on the basis of the observed intra- and intermolecular hydrogen bonds.

     

Zum Mechanismus der nucleophilen Addition an 2,3-Dihydrodipyrrin-1(10H)-one

¹H NMR-spectroscopic investigations of the acid catalyzed addition of methanol to dihydrodipyrrinones (Z)-2, (E)-2, and4 show the C-protonation of their enamide parts to be the first and rate determining step forming the key intermediate, the N-acyl-immonium ion N⁺. Its ability to add nucleophiles diastereoselectively can be used to prepare the adductsl-3 andl-5. Exclusive formation of thelike-isomer can be explained by a stereoelectronically favoured approach of the nucleophile and by the thermodynamically favoured arrangement of the bulky ring substituents. Both explanations are based on low temperature X-ray crystal structure determinations: in the first place, the orientation of the added nucleophile could be found to be nearly parallel to the -plane of the lactam unit and quasi-axial with respect to theenvelope-like conformation of the five-ring lactam; in the second place, the relative orientation of the methoxycarbonyl-metyl-group at C-3 and the pyrrolylmethyl-substituent at C-4 could be found to be atrans-quasi-diequatorial one.

     

Zur Reaktion von 4-Alkylaminodihydro-2(1H)-pyridinthionen bzw. -onen mit Ethylmalonsäure-bis-trichlorphenylester

4-Alkylamino-2(1H)-pyridinethiones (1) react with bis-trichlorphenylethylmalonate (3) to give four isomeric products: 5-thioxo-1,6-naphthyridine-2(1H)-ones (4), 7,7-dimethyl-4H-thiopyrano[2,3-b]pyridine-4-ones (6), 2,2-dimethyl-2H-thiopyrano[2,3-b]pyridine-5,7-dioles (7) and 2,2-dimethyl-2H-thiopyrano[2,3-b]pyridine-5(3H)-ones (8). On treatment with alkali the thioxogroup of4 is hydrolyzed and 1,6-naphthyridinediones (5) are formed. Compound5 can also be synthesized by heating the alkylaminopyridones (2) together with3.6 can be hydrolyzed to 2-thioxo-3-pyridylpropylketones (12). On treatment with diluted alkali or conc. acid the aminogroup of7 and8 is hydrolyzed and10 is formed. By heating in 20% NaOH10 is transformed to the dihydroxymercapto-3-pyridylmethylketone (11).

Herrn Prof. Dr.Erich Ziegler mit den besten Wünschen zum 70. Geburtstag gewidmet.     

The (E)/(Z)-ratio in the reaction of 5-(2-aryl-2-oxoethyl)-2-thioxo-4-oxo-1,3-thiazolidines with bromine

Summary 3-Aryl-, 3-benzyl-, and 3H-5-(2-aryl-2-oxoethyl)-2-thioxo-4-oxo-1,3-thiazolidines3a–h react with bromine in acetic acid solution to give mixtures of the respective 5-aroylmethylene (E) and (Z) diastereomeric derivatives5 and6. They contain more than 85% of the (E)-diastereomers along with some pure isomers. The intermediacy of the 5-bromo derivatives4 is proven and a plausible route of the reaction is presented. Structures of compounds3–6 are evidenced by analytical and spectral data.

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Das Verhältnis von (E)- und (Z)-Isomeren bei der Reaktion von 5-(2-Aryl-2-oxomethyl)-2-thioxo-4-oxo-1,3-thiazolidinen mit Brom

Zusammenfassung 3-Aryl-, 3-Benzyl- und 3H-5-(2-Aryl-2-oxoethyl)-2-thioxo-4-oxo-1,3-thiazolidine3a–h reagieren mit Brom in essigsaurer Lösung zu Gemischen der entsprechenden diastereomeren 5-Arylmethylen-Derivate ((E) und (Z))5 und6. Sie enthalten mehr als 85% des (E)-Diastereomeren. Die intermediäre Natur der 5-Brom-Derivate4 wird bewiesen; ein Reaktionsweg wird vorgeschlagen. Die Strukturen der Verbindungen3–6 werden durch analytische und spektroskopische Daten abgesichert.

     

The chemiluminescence of dispiro(1,2-dioxetane-diadamantane) sorbed on silipore activated by a phenanthroline complex of Eu(iii)

The thermal decomposition of dispiro(1,2-dioxetane-diadamantane) (1) sorbed on silipore containing EuCl₃ ando-phenanthroline was investigated. The observed chemiluminescence is caused by radiative deactivation of EU^*(iii) formed according to an energy transfer mechanism. Chemiluminescence decay in the course of the decomposition of1 is exponential with the rate constantk. The activation parameters of the decomposition of1 sorbed on silipore were determined from the temperature dependence ofk. These parameters are independent of the Eu(iii) content. A kinetic compensating effect was found: the dependence of logA onE _a as a function of the content of1. The mechanism of the compensating effect is discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 447–451, March, 1995.     

Conformational analysis 29: Preparation and1H and13C NMR,FTIR, MS,and crystallographic conformational and configurational study of 3-Oxo-1,3-oxathiane and its monomethyl derivatives

3-Oxo-1,3-oxathiane (1) and its monomethyl derivatives were prepared by oxidation of the corresponding 1,3-oxathianes. The structural analysis was carried out by¹H and¹³C NMR, FTIR, and mass spectrometry. At 298 K compound1 was a 1 1 (at 173 K a 3 1) mixture of the SO(ax) and SO(eq) chair forms. The major oxidation products of methyl 1,3-oxathianes attained exclusively the SO(ax), Me(eq) chair forms except that of the 5-methyl derivative, which consisted of 7% of the SO(eq), Me(ax) chair conformation in CDCl₃ solution. The minor products of oxidation existed in anancomeric SO(eq), Me(eq) chair conformations. The oxidation of 2-methyl- 1,3-oxathiane, however, led to 3,3-dioxo derivative (6) in addition to thetrans [SO(eq)] monoxide. The crystal structures of6 andtrans-3-oxo-5-methyl-1,3-oxathiane were solved by X-ray diffractometry.     

A study of the Claisen rearrangement of 7-(3-phenyl-2-propenyloxy)-3-phenyl-(4H)-1-benzopyran-4-one derivatives

Summary The Claisen rearrangement of 7-(3-phenyl-2-propenyloxy)-3-phenyl-(4H)-1-benzopyran-4-one (2 a) gave 7-hydroxy-8-(1-phenyl-2-propenyl)-3-phenyl-(4H)-1-benzopyran-4-one (3 a) and 2,3-dihydro-2,6-diphenyl-3-methyl-(7H)furo[2,3-h]-1-benzopyran-7-one (7 a). 2-Methyl-7-(3-phenyl-2-propenyloxy)-3-phenyl-(4H)-1-benzopyran-4-one (2 b) afforded4 b and7 b. 8-Methyl-7-(3-phenyl-2-propenyloxy)-3-phenyl-(4H)-1-benzopyran-4-one (12) gave only the alkali soluble product 7-hydroxy-8-methyl-6-(1-phenyl-2-propenyl)-3-phenyl-(4H)-1-benzopyran-4-one (13).3 a,4 b, and13 were further cyclized in acidic medium to9 a,10 b, and14 followed by dehydrogenation.This paper is dedicated to Dr. F. M. Dean, Department of Organic Chemistry, Robert Robinson Laboratories, University of Liverpool, Liverpool, U. K., on his retirement     

Overcrowded twisted bi-4H-cyclopenta[def]-phenanthren-4-ylidene versus bi-9H-fluorenylidene,syn pyramidalization

A crystal structure determination for bi-4H-cyclopenta[def]-phenanthren-4-ylidene, 1, reveals a molecular conformation rather like that reported earlier for bifluorenylidene,2. However, unexpectedly, the twist angle about the ethylenic linkage is substantially smaller in1 (average values are 30.8 and 40.7°, respectively). Comparison of bonding geometry, combined with the results of molecular mechanics calculations for1, demonstrates that syn pyramidalization can play an important role in determining a stable conformation for overcrowded, twisted aromatic enes. The average out-of-plane bending angles for the ethylenic carbon atoms of1 and2 are 8.6 and 4.4°, respectively.     

Synthese und Reaktionsverhalten von 3-(Bis(alkylthio)methylen)-3H-isobenzofuran-1-on-und 2-(Bis(alkylthio)methylen)-3(2H)-benzofuranon-Derivaten

Summary 3(Bis(alkylthio)methylene)-3H-isobenzofuran-1-ones2a–e and 2-(bis(alkylthio)methylene)-3(2H)-benzofuranone derivatives4a–c are obtained by reaction of phthalides1a–d or 3(2H)-benzofuranone (coumaranone3), respectively, with carbon disulfide under basic conditions followed by alkylation. The reaction behaviour of the new compounds2 and4 is investigated. 2-((2-Dimethylthio-1-oxo)ethyl)benzoic acid N,N-dimethylamide (7a) and 2-((2-dimethylthio-1-oxo)ethyl)-benzoic acid 2-methylpiperidide (7b) are surprisingly formed instead of the methylthio substitution products by treatment of2a with the corresponding amine in the presence of aluminum chloride.

Herrn Professor Dr. Dr. h. c.Waldemar Adam zum 60. Geburtstag gewidmet     

Synthesis,spectral, stereochemical and biological evaluation of (E)-2-(3-pentyl-2,6-diarylpiperidin-4-ylidene)-N-phenylhydrazinecarbothioamide derivatives

A series of new (E)-2-(3-pentyl-2,6-diarylpiperidin-4-ylidene)-N-phenylhydrazinecarbothioamides (1-6) were synthesized from the corresponding 3-pentyl-2,6-diarylpiperidine-4-ones condensation with phenyl thiosemicarbazide. Their chemical structures were confirmed by means of elemental analysis, FT-IR, ¹H, and ¹³C NMR spectral techniques and for compound 3, HOMOCOSY, HSQC, HMBC, NOESY, and DEPT NMR spectral techniques. From the NMR spectral data the compounds (1-6) are shown to exist in normal chair conformation with equatorial orientation of all the phenyl groups at C-2 and C-6 and pentyl group at C-3. The synthesized compounds were screened for their bacterial activity against Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi, and Escherichia coli and fungal activity against Candida albicans, Rhizopus sp, Aspergillus niger, and Aspergillus flasvus.     

4-Methylisocamphenilansäure und 4-(3,3,4-Trimethyl-2-exo-norbornyl)-3-buten-2-on

The synthesis of 4-methylisocamphenilanic acid (7) and of the unsaturated ketone 4-(3,3,4-trimethyl-2-exo-norbornyl)-3-buten-2-one (2), an analogue of -irone (1), are described. The preparation of2 has been accomplished by: catalyzedDiels—Alder reaction of methylcyclopentadiene and mesityl oxide, hydrogenation and isomerization of the resulting ketone mixture to theexo-ketone6, oxidation of6 to the acid7, reduction of7 to the corresponding aldehyde8 and aldol reaction of8 with acetone. The structure of the key intermediate6 was established by mass, 100 MHz¹H-NMR and¹³C-NMR spectra. The odour of2 is discussed briefly.

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Teil der Diplomarbeit vonI. Schmidmayer.

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9. Mitt.,G. Buchbauer undM. Wiltschko. J. Soc. Cosmet. Chem., im Druck.

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8. Mitt.,G. Buchbauer undE. Klissenbauer, Mh. Chem.109, 499 (1978).     

Synthesis of partially saturated N-substituted 4H-3,1-benzothiazine-2(1H)-thiones

Summary Acid-catalyzed reaction of 2-arylidenecyclohexanones1 with N-substituted dithiocarbamic acids2 gave open-chain addition products3 and4. Dehydration of3 and4 afforded only one of the three possible isomeric N-substituted 4H-3,1-benzothiazine-2(1H)-thiones5 and6.

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Synthese von partiell gesättigten N-substituierten 4H-3,1-Benzothiazin-2-(1H)-thionen

Zusammenfassung Die säurekatalysierte Reaktion von 2-Arylidencyclohexanonen1 mit N-substituierten Dithiocarbaminsäure2 ergab die offenkettigen Additionsprodukte3 und4. Die Dehydratation von3 und4 führte ausschließlich zu einem der drei möglichen N-substituierten 4H-3,1-Benzothiazin-2(1H)-thion-Isomeren5 und6.

     

Synthesis and X-ray structural investigation of 1,3,5-tris[4-(2-propynyloxy)phenyl]benzene

Synthesis and X-ray structural investigation of 1,3,5-tris[4-(2-propynyloxy)phenyl]benzene (1) were carried out. Compound1 is a trifunctional monomer for the synthesis of cross-linked polymers and a model of a section of polymeric network of this kind. In a crystal, the molecule of1 is located on the threefold symmetry axis and has a propeller-like conformation (the dihedral angle between the central and peripheral benzene rings is 35°). An essential feature of the crystal structure of1 is the proximity of the ethynyl groups of the neighboring molecules, which may be favorable to cyclotrimerization in the crystal. The spatial prerequisite to this process is the simultaneous rotation of the neighboring molecules1 about their symmetry axes by 10°. The displacements of the atoms in the reacting groups should amount to 1.6–1.8 Å.Deceased March, 1993.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1601–1605, September, 1993.     

Zur Struktur der Produkte der Reaktion vonE/Z-1-Benzolsulfonyl-3-(1-pentenyl)-indol mit N-Phenylmaleinimid: Ein erster Beitrag zur Konfigurations- und Konformationsanalyse in der Vinylindol-Cycloadditionsreihe

The products2,3 of the reaction ofE/Z-1-benzenesulfonyl-3-(1-pentenyl)-indole (1) and N-phenylmaleimide were analysed by¹H-NMR spectroscopy. Exemplarily, the structure elucidation of theendo-cyclo-adduct2 b was achieved by using several NMR techniques (diff. NOE-, INDOR-measurements, decoupling experiments, spectra simulation). The¹H-NMR-spectroscopically gained prediction of relative configuration and conformation of2 b was supported on X-ray analysis. The cyclohexene ring of the new cycloadducts adopts in the liquid phase and in the crystal a slightly twisted boat conformation.

     

Synthese von 4-(sec-Amino)-1,3-oxazin-2-onen und 4-(sec-Amino)-1,3-oxazin-2-thionen über elektrocyclische Ringschlußreaktion

The title compounds3 and4 are easily obtainable by reaction of 2-acyl-1-chloro-enamines2 with trimethylsilyl-isocyanate, trimethylsilyl-isothiocyanate or sodium rhodanide, respectively. Primarily formed acylvinyl-iso(thio)cyanatesD, G spontaneously undergo electrocyclization. A one-pot operation leads directly to 4-amino-1,3-oxazine-2-thiones4 starting from acylketenedichlorides1 via2 by successive addition of secondary amine and sodium rhodanide. Reaction of2 with ammonium dithiocarbamate results in an unexpected formation of4. Treatment of4 with mercuric acetate offers a further access to 4-amino-1,3-oxazine-2-ones3. Finally,3 are obtained from2 on the sequence of ammonolysis to acylketeneaminals5 and phosgenation. Characteristic scopes and limitations as well as mechanistic features of these transformations are discussed.

Herrn Prof. Dr.Klaus Hafner zum 60. Geburtstag gewidmet.     

Straightforward Preparation of (2E,4Z)-2,4-Heptadien-1-ol and (2E,4Z)-2,4-Heptadienal

Abstract

A concise synthesis of (2E,4Z)-2,4-heptadien-1-ol and (2E,4Z)-2,4-heptadienal is presented. Commercially available (Z)-2-penten-1-ol was converted to ethyl-(2E,4Z)-2,4-heptadienoate by reaction with activated MnO₂ and (carboethoxymethylene)triphenylphosphorane in the presence of benzoic acid as a catalyst. Ethyl-(2E,4Z)-2,4-heptadienoate was converted to (2E,4Z)-2,4-heptadien-1-ol with LiAlH₄. The alcohol was partially oxidized to (2E,4Z)-2,4-heptadienal with MnO₂. The title compounds are male-specific, antennally active volatile compounds from the Saltcedar leaf beetle, Diorhabda elongata Brulle (Coleoptera: Chrysomelidae) and have potential use in the biological control of the invasive weed saltcedar (Tamarix spp).     

Ein Beitrag zur Chemie des 2,3-Dihydro-3-oxo-benzo[b]thiophen-1,1-dioxids Synthesen mit Nitrilen, 86. Mitt.

Summary 2,3-Dihydro-3-oxo-benzo[b]thiophen-1,1-dioxide (1) reacts as CH-acidic component with amidines of orthoesters and anilines resp. to give the anilinomethylene derivates3, 4, and5. With triethyl orthoformiate the hydroxymethylene-compound7 is obtained. Anilino- and phenylhydrazino derivates8 and9 prove the carbonyl activity of1, azo-coupling leads to10, whereas treatment of1 with sulfur and malononitrile yields the benzo[b]thieno[2,3-d]thiophenes11. Introduction of substituents with active NH-functions in position 2 of the dicyanomethylene-product2, such as azocoupling, reaction with phenyl isocyanate and formation of enamines, leads to ring closure reactions between a nitrile and the NH-group. Thereby the phenyl-benzo[4,5]thieno[2,3-c]pyridazines12, the phenyl-1H-benzo[4,5]thieno[2,3-c]pyridines13 and the phenylamino-benzo[4,5]thieno[2,3-c]pyridines14 are obtained.¹³C and¹⁵N-NMR spectroscopy was used as proof of the ring closure reactions.

     

NMR studies of molecular motion in tetramethylammonium hydroxide pentahydrate

Polycrystalline (CH₃)₄NOH·5 H₂O (I) and (CH₃)₄NOD·5D₂O (II) have been studied by¹H NMR lineshapes, second moments and spin-lattice relaxation times and by²H NMR lineshapes as a function of temperature. From low temperatures the first motion to occur is reorientation of the internally rigid (CH₃)₄N⁺ ion about a uniqueC ₃ axis (E _ta = 8.37 kJ/mol forI,E _a = 9.00 kJ/mole forII), followed closely by pseudo isotropic reorientation of the whole ion (E _a = 18.10 kJ/mol). Motion of the cage molecules (water and hydroxide ion) occurs at higher temperatures with an apparentE _a = 11.30 kJ/mol. There is some evidence of a phase transition inII but notI in the 220–230 K region.²H NMR lineshapes ofII below 220 K indicate static cage molecules. Some of the²H quadrupole coupling constants derived from these spectra correspond to O·O hydrogen-bond distances which are incompatible with the known room temperature structure ofI. Above the possible transition inII the anisotropic²H lineshapes indicate rapid motion of²H among all possible hydrogen-bond sites via transfer along the bonds and molecular reorientation. This motion persists in the high temperature phase but the lineshape becomes isotropic due to the cubic symmetry of this phase. It is possible that¹H or²H tunnelling plays an important part in the motion of the cage molecules and the different phase behaviour ofI andII.Dedicated to Dr D. W. Davidson in honor of his great contributions to the sciences of inclusion phenomena.     

Crystal and Molecular Structures of (E)-(2-Phenylethenyl)cyclooctatetraene and (E)-(2-(4-Nitrophenyl)ethenyl)cyclooctatetraene. Conformations of Substituted Cyclooctatetraenes

The single crystal x-ray structures of (E)-(2-arylethenyl)cyclooctatetraenes 1 and 2 have been determined. The nitro group in 2 does not influence the geometry of the COT ring relative to that of 1. The influence of various substituents on several structural parameters of the COT ring are analyzed in terms of steric/electrostatic and electronegativity effects of the substituent.     

Molecular and crystal structure of 2-cyano-(2E)-pentadien-2,4-oic acid and ethyl-2-cyano-(2E)-pentadien-2,4-oate

X-ray study of 2-cyano-(2E)-pentadien-2,4-oic acid (1) and its ethyl ester (2) showed that the molecules of1 and2 in the crystalline phase form stacks by translating along the shortest crystallographic axis. The nature of the intermolecular interactions favoring the formation of such β-structures was analyzed within the framework of the Bader topological theory. Possible routes of topochemical reactions of compounds1 and2 are considered. Dedicated to the memory of Academician M. I. Kabachnik on his 90th birthday. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1991–1995, October, 1998.